package c.c0der.jsgl;

import android.content.Context;
import android.graphics.PixelFormat;
import android.opengl.GLSurfaceView;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;

import javax.microedition.khronos.egl.EGL10;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.egl.EGLContext;
import javax.microedition.khronos.egl.EGLDisplay;
import javax.microedition.khronos.opengles.GL10;

import static android.opengl.GLES10.glViewport;
import static android.opengl.GLES20.GL_COLOR_BUFFER_BIT;
import static android.opengl.GLES20.glClear;
import static android.opengl.GLES20.glClearColor;

public class MyGLSurface extends GLSurfaceView {
    private static final boolean DEBUG = true;
    private static final String TAG = "";
    private static int targetGLESVersion = 2;

    private static class MyRender implements Renderer {
        @Override
        public void onSurfaceCreated(GL10 gl, EGLConfig config) {
            glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
        }

        @Override
        public void onSurfaceChanged(GL10 gl, int width, int height) {
            glViewport(0, 0, width, height);
        }

        @Override
        public void onDrawFrame(GL10 gl) {
            Log.d("GL", "onDrawFrame");
            glClear(GL_COLOR_BUFFER_BIT);
        }
    }

    public MyGLSurface(Context context, Renderer renderer) {
        super(context);
        init(renderer);
    }

    public MyGLSurface(Context context, AttributeSet attrs, Renderer renderer) {
        super(context, attrs);
        init(renderer);
    }

    private void init(Renderer renderer) {
//
//        /*
//         * By default, GLSurfaceView() creates a RGB_565 opaque surface. If we want a translucent one, we should change the
//         * surface's format here, using PixelFormat.TRANSLUCENT for GL Surfaces is interpreted as any 32-bit surface with alpha by
//         * SurfaceFlinger.
//         */
//        getHolder().setFormat(PixelFormat.TRANSLUCENT);
//
//        /*
//         * Setup the context factory for 2.0 rendering. See ContextFactory class definition below
//         */
//        setEGLContextFactory(new ContextFactory());
//
//        /*
//         * We need to choose an EGLConfig that matches the format of our surface exactly. This is going to be done in our custom
//         * config chooser. See ConfigChooser class definition below.
//         */
//        setEGLConfigChooser(new ConfigChooser(8, 8, 8, 8, 16, 0));
        setEGLContextClientVersion(targetGLESVersion);
        setRenderer(renderer);
    }


    static class ContextFactory implements GLSurfaceView.EGLContextFactory {
        private static int EGL_CONTEXT_CLIENT_VERSION = 0x3098;

        public EGLContext createContext(EGL10 egl, EGLDisplay display, EGLConfig eglConfig) {
            Log.w(TAG, "creating OpenGL ES " + targetGLESVersion + ".0 context");
            checkEglError("Before eglCreateContext " + targetGLESVersion, egl);
            int[] attrib_list = {EGL_CONTEXT_CLIENT_VERSION, targetGLESVersion, EGL10.EGL_NONE};
            EGLContext context = egl.eglCreateContext(display, eglConfig, EGL10.EGL_NO_CONTEXT, attrib_list);
            boolean success = checkEglError("After eglCreateContext " + targetGLESVersion, egl);

            if ((!success || context == null) && targetGLESVersion > 2) {
                Log.w(TAG, "Falling back to GLES 2");
                targetGLESVersion = 2;
                return createContext(egl, display, eglConfig);
            }
            Log.w(TAG, "Returning a GLES " + targetGLESVersion + " context");
            return context;
        }

        public void destroyContext(EGL10 egl, EGLDisplay display, EGLContext context) {
            egl.eglDestroyContext(display, context);
        }
    }

    static boolean checkEglError(String prompt, EGL10 egl) {
        int error;
        boolean result = true;
        while ((error = egl.eglGetError()) != EGL10.EGL_SUCCESS) {
            result = false;
            Log.e(TAG, String.format("%s: EGL error: 0x%x", prompt, error));
        }
        return result;
    }

    private static class ConfigChooser implements GLSurfaceView.EGLConfigChooser {

        public ConfigChooser(int r, int g, int b, int a, int depth, int stencil) {
            mRedSize = r;
            mGreenSize = g;
            mBlueSize = b;
            mAlphaSize = a;
            mDepthSize = depth;
            mStencilSize = stencil;
        }

        /*
         * This EGL config specification is used to specify 2.0 rendering. We use a minimum size of 4 bits for red/green/blue, but
         * will perform actual matching in chooseConfig() below.
         */
        private static int EGL_OPENGL_ES2_BIT = 4;
        private static int[] s_configAttribs2 = {EGL10.EGL_RED_SIZE, 4, EGL10.EGL_GREEN_SIZE, 4, EGL10.EGL_BLUE_SIZE, 4,
                EGL10.EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT, EGL10.EGL_NONE};

        public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display) {

            /*
             * Get the number of minimally matching EGL configurations
             */
            int[] num_config = new int[1];
            egl.eglChooseConfig(display, s_configAttribs2, null, 0, num_config);

            int numConfigs = num_config[0];

            if (numConfigs <= 0) {
                throw new IllegalArgumentException("No configs match configSpec");
            }

            /*
             * Allocate then read the array of minimally matching EGL configs
             */
            EGLConfig[] configs = new EGLConfig[numConfigs];
            egl.eglChooseConfig(display, s_configAttribs2, configs, numConfigs, num_config);

            if (DEBUG) {
                printConfigs(egl, display, configs);
            }
            /*
             * Now return the "best" one
             */
            return chooseConfig(egl, display, configs);
        }

        public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display, EGLConfig[] configs) {
            for (EGLConfig config : configs) {
                int d = findConfigAttrib(egl, display, config, EGL10.EGL_DEPTH_SIZE, 0);
                int s = findConfigAttrib(egl, display, config, EGL10.EGL_STENCIL_SIZE, 0);

                // We need at least mDepthSize and mStencilSize bits
                if (d < mDepthSize || s < mStencilSize) continue;

                // We want an *exact* match for red/green/blue/alpha
                int r = findConfigAttrib(egl, display, config, EGL10.EGL_RED_SIZE, 0);
                int g = findConfigAttrib(egl, display, config, EGL10.EGL_GREEN_SIZE, 0);
                int b = findConfigAttrib(egl, display, config, EGL10.EGL_BLUE_SIZE, 0);
                int a = findConfigAttrib(egl, display, config, EGL10.EGL_ALPHA_SIZE, 0);

                if (r == mRedSize && g == mGreenSize && b == mBlueSize && a == mAlphaSize)
                    return config;
            }
            return null;
        }

        private int findConfigAttrib(EGL10 egl, EGLDisplay display, EGLConfig config, int attribute, int defaultValue) {

            if (egl.eglGetConfigAttrib(display, config, attribute, mValue)) {
                return mValue[0];
            }
            return defaultValue;
        }

        private void printConfigs(EGL10 egl, EGLDisplay display, EGLConfig[] configs) {
            int numConfigs = configs.length;
            Log.w(TAG, String.format("%d configurations", numConfigs));
            for (int i = 0; i < numConfigs; i++) {
                Log.w(TAG, String.format("Configuration %d:\n", i));
                printConfig(egl, display, configs[i]);
            }
        }

        private void printConfig(EGL10 egl, EGLDisplay display, EGLConfig config) {
            int[] attributes = {EGL10.EGL_BUFFER_SIZE, EGL10.EGL_ALPHA_SIZE, EGL10.EGL_BLUE_SIZE, EGL10.EGL_GREEN_SIZE,
                    EGL10.EGL_RED_SIZE, EGL10.EGL_DEPTH_SIZE, EGL10.EGL_STENCIL_SIZE, EGL10.EGL_CONFIG_CAVEAT, EGL10.EGL_CONFIG_ID,
                    EGL10.EGL_LEVEL, EGL10.EGL_MAX_PBUFFER_HEIGHT, EGL10.EGL_MAX_PBUFFER_PIXELS, EGL10.EGL_MAX_PBUFFER_WIDTH,
                    EGL10.EGL_NATIVE_RENDERABLE, EGL10.EGL_NATIVE_VISUAL_ID, EGL10.EGL_NATIVE_VISUAL_TYPE,
                    0x3030, // EGL10.EGL_PRESERVED_RESOURCES,
                    EGL10.EGL_SAMPLES, EGL10.EGL_SAMPLE_BUFFERS, EGL10.EGL_SURFACE_TYPE, EGL10.EGL_TRANSPARENT_TYPE,
                    EGL10.EGL_TRANSPARENT_RED_VALUE, EGL10.EGL_TRANSPARENT_GREEN_VALUE, EGL10.EGL_TRANSPARENT_BLUE_VALUE, 0x3039, // EGL10.EGL_BIND_TO_TEXTURE_RGB,
                    0x303A, // EGL10.EGL_BIND_TO_TEXTURE_RGBA,
                    0x303B, // EGL10.EGL_MIN_SWAP_INTERVAL,
                    0x303C, // EGL10.EGL_MAX_SWAP_INTERVAL,
                    EGL10.EGL_LUMINANCE_SIZE, EGL10.EGL_ALPHA_MASK_SIZE, EGL10.EGL_COLOR_BUFFER_TYPE, EGL10.EGL_RENDERABLE_TYPE, 0x3042 // EGL10.EGL_CONFORMANT
            };
            String[] names = {"EGL_BUFFER_SIZE", "EGL_ALPHA_SIZE", "EGL_BLUE_SIZE", "EGL_GREEN_SIZE", "EGL_RED_SIZE",
                    "EGL_DEPTH_SIZE", "EGL_STENCIL_SIZE", "EGL_CONFIG_CAVEAT", "EGL_CONFIG_ID", "EGL_LEVEL", "EGL_MAX_PBUFFER_HEIGHT",
                    "EGL_MAX_PBUFFER_PIXELS", "EGL_MAX_PBUFFER_WIDTH", "EGL_NATIVE_RENDERABLE", "EGL_NATIVE_VISUAL_ID",
                    "EGL_NATIVE_VISUAL_TYPE", "EGL_PRESERVED_RESOURCES", "EGL_SAMPLES", "EGL_SAMPLE_BUFFERS", "EGL_SURFACE_TYPE",
                    "EGL_TRANSPARENT_TYPE", "EGL_TRANSPARENT_RED_VALUE", "EGL_TRANSPARENT_GREEN_VALUE", "EGL_TRANSPARENT_BLUE_VALUE",
                    "EGL_BIND_TO_TEXTURE_RGB", "EGL_BIND_TO_TEXTURE_RGBA", "EGL_MIN_SWAP_INTERVAL", "EGL_MAX_SWAP_INTERVAL",
                    "EGL_LUMINANCE_SIZE", "EGL_ALPHA_MASK_SIZE", "EGL_COLOR_BUFFER_TYPE", "EGL_RENDERABLE_TYPE", "EGL_CONFORMANT"};
            int[] value = new int[1];
            for (int i = 0; i < attributes.length; i++) {
                int attribute = attributes[i];
                String name = names[i];
                if (egl.eglGetConfigAttrib(display, config, attribute, value)) {
                    Log.w(TAG, String.format("  %s: %d\n", name, value[0]));
                } else {
                    // Log.w(TAG, String.format("  %s: failed\n", name));
                    while (egl.eglGetError() != EGL10.EGL_SUCCESS)
                        ;
                }
            }
        }

        // Subclasses can adjust these values:
        protected int mRedSize;
        protected int mGreenSize;
        protected int mBlueSize;
        protected int mAlphaSize;
        protected int mDepthSize;
        protected int mStencilSize;
        private int[] mValue = new int[1];
    }
}
